quote:
I am reading in here that a CF/SH oil like 5-30 dino XD3 can actually have better wear additive packages in the SH formulation than SL rated oil?
If the application is an engine design, typical of older vehicles, with components exposed to a higher % of sliding friction, then the 1200 ppm ZDDP levels of SH/SJ oils may be beneficial.
But remember, reduced levels of ZDDP for SL and now SM, does not equal weak anti-wear performance. Many other additives are now providing AW protection in GF-4 oils. These oils must also pass the Sequence IIIG engine wear test which was upgraded from 80 to 100 hours.
quote:
It is my my understanding in reading that SH oil was actually reduced in additives to prevent Cat Converter poisening, is this true?
Not exactly. ZDDP was not reduced as a response to Cat's failing from phosphorous poisoning.
It was reduced originally in response to environmental concerns and most recently as a safe guard for when the auto mfg's are required to warranty Cats for 120K miles.
I still would like to see some actual data that indicates how many quarts of SH/SJ oil, consumed during normal driving cycles,(is it 50 or 100?)would actually deactivate the catalyst.
Or, at normal addive depletion rates due to volatility, what levels of ZDDP, is it 2000 or 5,000 ppm, would be required to affect the Cat over 120K miles?
